The present disclosure relates to a congestion information generation device for generating road congestion information and a congestion information generation method.
In techniques of generating road congestion information in real time and providing the information to automobiles has been known, such congestion information may be convenient when provided for more roads as more detailed information. However, in a technique of generating congestion information based on information obtained from sensors provided on road sides, for example, the road for which the congestion information is generated is limited to roads on which sensors are provided, and it may be difficult to obtain information on the length of congestion and the like. Therefore, an example of a technique of generating congestion information based on the position information and the time information of mobile terminals that are moving on a road is proposed in Japanese Laid-Open Patent Publication No. 2012-137835.
A congestion information generation device disclosed in Japanese Laid-Open Patent Publication No. 2012-137835 includes a GPS information collecting means and a link velocity calculating means. The GPS information collecting means stores matching position information, at which GPS position information measured by mobile terminals matches a road link in a storage device in correlation with a road link ID together with position measurement time information corresponding to the GPS position information. The link velocity calculating means calculates a moving velocity of the mobile terminal based on the distance and the difference in position measurement time between a matching position closest to a starting point of a subject road link and a matching position closest to an ending point of the subject road link, among a plurality of matching positions present successively in time in the subject road link. The congestion information generation device generates congestion information of the subject road link based on the calculated moving velocity.
According to the congestion information generation device disclosed in Japanese Laid-Open Patent Publication No. 2012-137835, it is possible to generate congestion information of a road on which a mobile information device (mobile terminal) moves as well as a road in which sensors are provided on road sides. However, it may not be said that all the mobile information devices from which the position information is acquired are held by the occupants of travelling automobiles. Thus, when the congestion information is generated from velocity data obtained based on the position information and the time information acquired from a mobile information device, the velocity data also includes a velocity obtained based on the information of a mobile information device held by a pedestrian rather than an occupant of a travelling automobile, an occupant of a parked automobile, and the like. When the velocity data includes the velocity obtained based on the information of mobile information devices held by users who are not in the travelling automobile, the accuracy of the congestion information generated based on the velocity will be low.
Thus, embodiments of the present disclosure provide congestion information generation devices and methods that may improve accuracy of road congestion information generated from velocity based on information obtained from a mobile information device.